public class BlockSearch {
    public static void main(String[] args) {
        //要先手动分块
        int[] arr={16,5,9,12,21,18,
                   32,23,37,26,45,34,
                   50,48,61,52,73,66};

        //创建三个块对象
        Block b1=new Block(21,0,5);
        Block b2=new Block(45,6,11);
        Block b3=new Block(73,12,17);

        Block[] blockArr={b1,b2,b3};

        //要找的元素
        int num1=30;
        int num2=52;

        int index1=getIndex(blockArr,arr,num1);
        int index2=getIndex(blockArr,arr,num2);

        System.out.println(index1);
        System.out.println(index2);

    }

    public static int getIndex(Block[] blockArr,int[] arr,int num){
        //确定num在哪块
        int indexBlock=findIndexBlock(blockArr,num);

        if(indexBlock==-1){
            return -1;
        }

        int startIndex=blockArr[indexBlock].getStartIndex();
        int endIndex=blockArr[indexBlock].getEndIndex();

        //遍历
        for (int i = startIndex; i <endIndex ; i++) {
            if(arr[i]==num){
                return i;
            }
        }
        return -1;
    }

    //找到数在哪块
    public static int findIndexBlock(Block[] blockArr,int num){
        for (int i = 0; i < blockArr.length; i++) {
            if(num<=blockArr[i].getMax()){
                return i;
            }
        }
        return -1;
    }
}

class Block{
    private int max;
    private int startIndex;
    private int endIndex;


    public Block() {
    }

    public Block(int max, int startIndex, int endIndex) {
        this.max = max;
        this.startIndex = startIndex;
        this.endIndex = endIndex;
    }

    /**
     * 获取
     * @return max
     */
    public int getMax() {
        return max;
    }

    /**
     * 设置
     * @param max
     */
    public void setMax(int max) {
        this.max = max;
    }

    /**
     * 获取
     * @return startIndex
     */
    public int getStartIndex() {
        return startIndex;
    }

    /**
     * 设置
     * @param startIndex
     */
    public void setStartIndex(int startIndex) {
        this.startIndex = startIndex;
    }

    /**
     * 获取
     * @return endIndex
     */
    public int getEndIndex() {
        return endIndex;
    }

    /**
     * 设置
     * @param endIndex
     */
    public void setEndIndex(int endIndex) {
        this.endIndex = endIndex;
    }

    public String toString() {
        return "Block{max = " + max + ", startIndex = " + startIndex + ", endIndex = " + endIndex + "}";
    }
}
